Traverse linearity compensation method and rotational accuracy compensation method of measuring device

Abstract

A compensation method according to the present invention includes: a traverse linearity data calculating step for measuring a master workpiece (MW) of which profile data is value-specified in advance while moving a sensor ( 7 ) using a linear movement mechanism ( 4, 5 ) of a measuring device ( 1 ) and for subtracting the previously value-specified profile data from the measurement data of the master workpiece to obtain a traverse linearity data of the linear movement mechanism; a workpiece measurement data calculating step for measuring the workpiece while moving the sensor by the linear movement mechanism of the measuring device to obtain a measurement data of the workpiece; and a workpiece profile calculating step for subtracting the traverse linearity data from the workpiece measurement data to obtain a true value data of the workpiece.

What is claimed is:  
     
       1. A traverse linearity compensation method of a measuring device having a linear movement mechanism, the method comprising: 
       a traverse linearity data calculating step for measuring a master workpiece of which profile data is value-specified in advance by a master workpiece measuring device for measuring errors in the master workpiece while moving a sensor by the linear movement mechanism of the measuring device and for subtracting the value-specified profile data from the master workpiece measurement data to obtain a traverse linearity data of the linear movement mechanism;  
       a workpiece measurement data calculating step for measuring a workpiece while moving the sensor by the linear movement mechanism of the measuring device to obtain a measurement data of the workpiece; and  
       a workpiece profile calculating step for subtracting the traverse linearity data from the workpiece measurement data to obtain a true value data of the workpiece.  
     
     
       2. The traverse linearity compensation method of a measuring device having a linear movement mechanism according to  claim 1 , further comprising: 
       a traverse linearity data storing step for storing the traverse linearity data obtained in the traverse linearity data calculating step;  
       a workpiece measurement data storing step for storing the workpiece measurement data obtained in the workpiece measurement data storing step; and  
       a data reading and workpiece profile calculating step for reading out the stored workpiece measurement data and the traverse linearity data stored in the respective storing steps, wherein the workpiece profile calculating step subtracts the traverse linearity data from the workpiece measurement data to obtain a true value data of the workpiece.  
     
     
       3. The traverse linearity compensation method of a measuring device according to  claim 1 , wherein a measurement jig having a mount provided with a workpiece mounting surface and a origin-setting reference ball buried in the mount or the master workpiece with a part thereof being exposed is used in the traverse linearity data calculating step, and 
       wherein, after a square-pillar master workpiece is rested on the workpiece mounting surface of the mount and a measurement origin is set by locating the sensor of the measuring device on a vertex of the reference ball, the sensor is moved along a side of the master workpiece by the linear movement mechanism to measure the master workpiece.  
     
     
       4. The traverse linearity compensation method of a measuring device according to  claim 3 , wherein the mount is formed in a half-cylinder having a vertical reference surface orthogonal with the workpiece mounting surface, the reference ball being buried on the vertical reference surface with a part thereof being exposed. 
     
     
       5. A rotational accuracy compensation method of a measuring device having a rotary mechanism, the method comprising: 
       a rotational accuracy data calculating step for measuring a profile of a master workpiece by a sensor while the rotary mechanism of the measuring device rotates a master workpiece of which profile data at a data acquisition position is value-specified in advance by a master workpiece measuring device for measuring errors in the master workpiece and for subtracting the value-specified profile data from the master workpiece measurement data to obtain a rotational accuracy data of the rotary mechanism;  
       a workpiece measurement data calculating step for measuring the profile of the workpiece by the sensor while rotating the workpiece by the rotary mechanism, of the measuring device to obtain a measurement data of the workpiece; and  
       a workpiece profile calculating step for subtracting the rotational accuracy data from the workpiece measurement data to obtain a true value data of the workpiece.  
     
     
       6. The rotational accuracy compensation method of a measuring device having a rotary mechanism according to  claim 5 , further comprising: 
       a rotational accuracy data storing step for storing the rotational accuracy data obtained in the rotational accuracy data calculating step;  
       a workpiece measurement data storing step for storing the workpiece measurement data obtained in the workpiece measurement data calculating step; and  
       a data reading and workpiece profile calculating step for reading out the workpiece measurement data and the rotational accuracy data stored in the respective storing steps, wherein the workpiece profile calculating step subtracts the rotational accuracy data from the workpiece measurement data to obtain a true value data of the workpiece.  
     
     
       7. The rotational accuracy compensation method according to  claim 5 , wherein a measurement jig provided with a cylindrical mount having a hemispherical master workpiece on an upper surface thereof and an origin-setting reference ball buried in the mount or the master workpiece with a part thereof being exposed is used, and 
       wherein, after a measurement origin is set by locating a sensor of the measuring device to a vertex of the reference ball, the sensor is located to the data acquisition position of the master workpiece and the master workpiece is measured while rotating the master workpiece by the rotary mechanism.